Design ErrorService (UI + Code Bihind)

[fbarresi]

The error service should have the following functionalities

• [ ] observe different variables from different plcs
• [ ] allow to define error conditions for every variables
• [ ] allow different severity (Fatal, Error, Warning, Info)
• [ ] allow to define actions and messages for every error state
• [ ] allow to define severity level for each error for manage priority
• [ ] keep an audit log for every new event (error state becomes true or false)